1. Field of the Invention
The present invention relates to an emergency exit sign having a beacon module for indoor positioning, and an indoor positioning system using the same. More particularly, the present invention relates to a technology capable of simply building an indoor positioning system at a low cost, by installing a beacon module for indoor positioning in an emergency exit sign to make accurate indoor positioning possible.
2. Description of the Related Art
In recent years, an initial Global Positioning System (GPS) technology developed for military use is being widely used for civilian purposes of navigation, measurement, cartography and the like. Also, even a Location Based Service (LBS) using a GPS receiver as a positioning sensor has been commercialized.
But, it frequently occurs that the GPS receiver cannot receive a GPS satellite signal within doors, a metropolitan area of many high-rise buildings, an underground parking lot, a subway, a tunnel and the like. For this reason, there is a problem that the GPS receiver cannot provide consecutive user location information to a user indoors.
To fix this problem, many researches have been made on an indoor positioning technology of installing an Access Point (AP) within a building and enabling the AP to locate a target within doors using a Radio Frequency (RF) signal, and a service based on this. Active researches have been made on wireless indoor positioning technologies using infrared rays, ultrasonic waves and the like in addition to the RF signal.
The RF signal based indoor positioning technology is a technology of locating a target through a relative Received Signal Strength Indication (RSSI) received from a previously installed access point. The infrared ray based indoor positioning technology is a technology in which infrared sensors installed throughout the indoor recognize an infrared device having a unique IDentifier (ID) code and locate the infrared device. The ultrasonic wave based indoor positioning technology is a technology of locating a target using a transfer rate difference between a fast RF signal and a relative slow ultrasonic wave.
However, the aforementioned indoor positioning technologies excepting the ultrasonic wave based indoor positioning technology have a disadvantage of generally not only causing a large measurement error but also requiring very many access points, infrared sensors or the like. Also, because even an error of positioning information measurement is great more than a few meters, many inconveniences of use are caused.
Owing to the characteristic in which an RF signal is difficult to permeate walls, in many cases, the RF signal based indoor positioning technology is difficult to detect an accurate current location of a user within doors and is also difficult to detect an accurate location of the user between floors. Further, owing to a limitation on a basic reception distance of infrared rays, the infrared ray based indoor positioning technology has a problem that service is restrictive, and the cost of system installation and maintenance is very high. Further, the ultrasonic wave based indoor positioning technology enables accurate measurement, but has a problem that the cost of system installation is very high.
That is, the conventional indoor positioning technologies have a problem of having to bear the investment cost for expensive system building, because they cannot implement indoor positioning if an expensive indoor positioning system is not equipped.